[PATCH rdma-next 06/23] RDMA/mlx5: Require IB_QPT_DRIVER for the DC vendor QP types

[Yishai Hadas <yishaih@nvidia.com>]

check_qp_type() checks the dct capability only for IB_QPT_DRIVER, but
process_vendor_flags() turns any QP that carries a DC type flag into a
DCI or DCT QP. A QP created as, for example, IB_QPT_RC with a DC flag
thus becomes a DC QP without the capability check.

Accept the DC type flags only on IB_QPT_DRIVER, the type userspace
uses to create DC QPs.

Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
---
 drivers/infiniband/hw/mlx5/qp.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index 943ee5c55538..19cbf6b2b979 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -2965,18 +2965,22 @@ static int process_vendor_flags(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp,
 
 	switch (flags & (MLX5_QP_FLAG_TYPE_DCT | MLX5_QP_FLAG_TYPE_DCI)) {
 	case MLX5_QP_FLAG_TYPE_DCI:
+		if (qp->type != IB_QPT_DRIVER)
+			return -EINVAL;
 		qp->type = MLX5_IB_QPT_DCI;
 		break;
 	case MLX5_QP_FLAG_TYPE_DCT:
+		if (qp->type != IB_QPT_DRIVER)
+			return -EINVAL;
 		qp->type = MLX5_IB_QPT_DCT;
 		break;
+	case 0:
+		/* IB_QPT_DRIVER needs a subtype */
+		if (qp->type == IB_QPT_DRIVER)
+			return -EINVAL;
+		break;
 	default:
-		if (qp->type != IB_QPT_DRIVER)
-			break;
-		/*
-		 * It is IB_QPT_DRIVER and or no subtype or
-		 * wrong subtype were provided.
-		 */
+		/* Both subtypes */
 		return -EINVAL;
 	}
 
-- 
2.18.1